Type of Cell

Cell is the structural & functional unit of living organism.

Type of cell:

On the basis of the structure of nucleus cell is of two types –

1. Prokaryotic cell (e.g Bacteria)
2. Eukaryotic cell (e.g Human cell)

On the basis of physiological function cell is of two types -

1. Somatic cell (Body cell)
2. Sex cell (Reproductive cell)

Function of a cell: 

1. Function & assimilation – the process by which food substances are taken into the cells of the body after they have been digested & absorbed.

2. Growth & repair – Development & regeneration of organs.

3. Metabolism – the sum of all the chemical & physical changes that takes place within the body.

4. Respiration – the process of gaseous exchange.

5. Excretion - elimination of wastes product from the body.

6. Irritability & conductivity – Response to stimuli & communication with other cell.

Organelles (components) of cell:

A cell consists of –

1. Cell membrane – a semi-permeable membrane covering protoplasm. It protect the cell organelles.

2. protoplasm – it consist of Cytoplasm & Nucleus.

3. Cytoplasm – Except nucleus the rest of cell body is called Cytoplasm.

Organelles of Cytoplasm :

1. It consist of-
2. mitochondria: Rod-lide structure & is called power house of cell. Energy stored as ATP (Adenosine Triphosphate).
3. Endoplasmic Reticulum: It is a system of interconnecting membrane bound channels within the cytoplasm. Participate in protein synthesis.
4. Golgy body : Canal – like structure that helps in synthesis of carbohydrate cell membrane.
5. Lysosome:  Are tiny granules composed of RNA (Ribo Nucleic Acid) (65% & Protein (35%). It consists of subunits: Large – 50s & Smaller – 30s. Synthesize cytoplasmic protein.

Nucleus:

Centrally located a round mass is called nucleus. It is separated from cytoplasm gy a nuclear membrane. It contains 46 chromosomes of which 23 from mother & 23 from father that contain genes. Genes are composed of DNA (Deoxyribo Nucleic Acid – double helix structure of (chromosomes).

Chromosome:

There is some chromatin threads present in
the nucleus, called chromosome.
Chromosomes are the vital to the
everyday activities of the cell &
responsible for determining the hereditary
characteristics of the human body.

Functions of Nucleus:

1. It produces Ribosome.
2. Synthesize RNA & protein.
3. It inherits the character to the offspring through genes.
4. It influences growth & initiates divisions or reproduction of cell.

Parts of nucleus

1. Nuclear membrane
2. Nucleoplasm
3. Nucleolus
4. Nuclear reticulum or chromatin.

Structure of a cell

Read more »

Posted in: about cells,cell,cell structure,cells structure and function,types of cell,what is a human cell

Types of Tissue

Collection of cell having similar structure & performing a common physiological function is called tissue.

Types of Tissue:

1. Epithelial tissue: Covering the external & internal body surfaces. e.g. – Skin, internal covering of GIT.
2. Connective tissue: Connects different structures of the body & also helps to provide framework of the body. e.g. – Blood, Bones.
3. Muscular tissue;: Muscular tissues make up the major part of the soft tissues of the body & by means of its contraction power helps in locomotion. e.g. – Skeletal muscle, cardiac muscle.
4. Nervous tissue: Nervous tissue is highly specialized tissue which controls & co-ordinates the body functions by forming nervous system. e.g – Neuralgia, White matter, Grey matter.

Read more »

Posted in: connective tissu,epithelial tissues,muscle tissue,nervous system,tissues,types of tissue,what is physiological

The Human Ear

The ear is the organ of hearing & also plays an important part in the maintenance of balance. It has three parts- outer, middle & inner. The outer ear consists of ear canal & eardrum. The middle ear consists of ear ossicles (Malleus, Incus, Stapes), Eustachian tube & Cavity. The inner ear consist of semicircular canals, fenestra ovalis, vestibule cochlear nerve, fenestra rotunda &  cochlea.

The Ear

Read more »

Posted in: anatomy ear,ear diagram,hearing,parts of the ear,the ear

The Human Eye

The eye is the organ of sight & is situated in the orbit which protects it from injury. The eye is spherical in shape & embedded in fat. it has three coats – the outer fibrous coat, the middle vascular coat & the inner nervous coat. the outer coat consist of Sclera, Conjunctiva & Cornea. the middle coat consist Choroid, Cilliary body & Iris. The inner coat is Retina.

Human Eye

Read more »

Posted in: anatomy of the eye,eye,eye functions,for eyes,picture of eye

The Human Skin

The skin is one of the human body’s largest organs. Skin contains sensory devices that monitor the external environment. The nerves in skin receive the stimuli that are then interpreted by the brain as touch, heat, & cold.

Skin is composed of three layers:

1. Epidermis -               the outer layer.

2. Dermis -                   the middle layer.

3. Subcutaneous -         the inner layer.
 

Read more »

Posted in: epidermis skin,layers of skin,skin,skin diagram,what are skin cells